Slugging is a problem that is especially related to mature oil fields. As an oil well ages, the downhole pressure reduces, and gases and liquids in the multiphase hydrocarbons tend to separate in the flowlines and risers as the flowlines travel down a decline to a subsequent incline. Typically, this is due to the heavier liquids moving faster than corresponding gases, which results in the formation of liquid and gas pockets (also called slugs). The formation of slugs can result in large pressure and production fluctuations. Such pressure and production fluctuations can give rise to operational hazards and can damage downstream equipment.
Such slugging problems can also arise on land when piping multiphase hydrocarbons. Slugging can also occur at the intersection of a downwardly inclined portion of pipeline with an upwardly inclined portion of pipeline, such as through terrain having hills or mountains, which is known in the art as “terrain induced slugging”.